I know that algae growth can be caused by a number of factors, but Im looking for the most obvious to start, im willing to work to narrow this down.

I've got some hair algae growing over a lot of my plants, it tends to be the older growth as opposed to the newer growth, but that might just be because it hasnt had time to grow yet. I have not noticed any nitrates in the water, so I dont think thats the problem. I do an ~10-20% water change once per week. The tank is a 55 gal. planted south american blackwater, but the water is more yellowish than it is brown. I've been running about 3wpg over the tank for 12 hours per day. So, what should I do to reduce the algae?

Yesterday I pulled some microsword that was growing amoungst my val forest (you can check out my tank to see what I mean) and it had no algae growth on it, as opposed to the val, which is pretty covered, or the microsword that is in the "open". Now, because of the location, I would assume it was getting less light than most of my other plants, and it was algae free. So, would it be a good idea to drop my light to 2wpg?

Another thing I noticed was some yellowing of the leaves of my amazon sword, and some holes in the leaves of my cryptocorne, which, in my experience mean a lack of nutrients, so should I up the ferts to twice a week?

Originally, I had 2wpg and dosed ferts 2x per week. Everything seemed swell, moderate algae, but nothing too bad. I wanted to grow carpet plants, and was told 3wpg would be necessary, so I upped the light. I run a 2L DIY co2 connected to a wood microbubble stone as well. I had a bad outbreak of algae, so I put the tank into blackout, and decided to reduce ferts to once per week. This worked fine for a little while. but it wasnt algae free or anything. Now the algae is back (I might have left the lights on for longer than 12 hours for a couple of days though....its on a timer now), and I'm back to fighting the battle I dont want to be. Im looking for suggestions on how to keep this algae in check, especially since the beard algae is next to impossible to remove from my plants, and my oto's and BN dont seem to eat it.

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Hmm, I'm no expert with aquatic plants but a few things spring to mind:

It sounds like the plants need to get a hold over the algae but just aren't able to do so as it's already got quite a hold so;

Have you tried Crossocheilus siamensis? I found them to be an excellent algae eater in my planted tank, to the extent that I couldn't get any to grow anywhere. One in my 55 was enough to keep the whole thing spotless.

If the siamensis is able to knock the algae back you might be able to increase the ferts to a dose where the plants are able to really rocket ahead so that THEY become the dominant organic matter... Fully utilizing the amount of light you're giving them. You need to get the plants a foothold over the algae.

What exactly is your light cycle? I found that providing a couple of breaks during the day also helped to ensure that algae couldn't get a stronghold. As long as you give the plants 4-5 hours of continuous light they are able to photosynthesise efficiently, so work the 1/2 hour - 1 hour breaks around this requirement.

How do you control your co2 saturation?

How do you dose and measure your dosing?

What are your NitrAtes?

I used EI with 50% weekly water changes and had great success, the key may well be in simply upping your water changes (phosphorous builds up and algae uses that stuff to grow like nuts!).

I find it really odd that you'd read 0 nitrates, not in a cycled tank, even if heavily planted. Something funny about that. What test kit are you using?

Is there any way you can get a phosphate reading?

Again, do you have ANY breaks during your light cycle or is it on a solid 12 hours?

I reckon something as simple as a 50% weekly waterchange and an interruption or two in that solid light cycle might be what it takes to help get the plants back on top, it's only because the algae has had it's chance and become dominant that they're struggling so much. Healthy, fast growing plants will pretty much keep algae at bay themselves - I found sticking Hygrophilia in helped if I was having the start of an algae outbreak - the stuff grows so rigorously it outdoes the algae.

ill have to check the kit, I only bought it a couple of months back....aquarium pharmaceuticals, the liquid test is the one im using. It was not sitting on the shelf too long before I bought it....I do find it odd that I keep reading zero though too.

Phosphate reading....I couldnt find a kit that does phosphate at my local petco (my reliable lfs's are 30 mins away, so for gas reasons, I only go there once a month or so, I can check there in a few weeks). Is there a particular kit, or is there a different way of getting that reading?

My photoperiod is 12 straight hours. I can put a break in the middle of it for an hour or so if it helps. Would reducing it to 10 hours also be a good idea? Currently I dropped everything to 2wpg to see if things improve.

I've thought about putting hygro in there to suck up some of the neutrients...you can take a look at my tank in my sig, where would I put it? Maybe I will go that way though. I'll also look at adding an extra waterchange to my regiment (at least for the time being). I would love to do a 50% water change, but thats just not possible for me. I get my RO water from work in buckets, two buckets worth is what I can manage easily without it becoming a problem. (I know, I know, get an RO unit....its on the wish list, but they are still pretty expensive).

I'm doing everything by the book, bought all the goods and my plants are growing like weeds and so is my algae, BBA on the edges of leaves mostly. I think it's a lifelong wild goose chase but Amano has pristine tanks and so do many others but IMHO it's an art and I'm no artist.

Ok, so donfish and bairo1, thanks very much for your help. Im thinking that I just had too much light on the tank. So, now on to a couple of things I should change.

Im not growing any high maintenance high light plants, so 2wpg should be fine. Im hoping this is still enough for the pygmy and microsword to grow. Since I use peat in the filter, the tank is a little darker than a normal tank, but I guess its not enough to warrent pumping the extra light over it. I think im better off reducing the light since co2 injection to grow sword plants and val seems, whats the word...oh yea, complete overkill. So, I will try to get up to the lfs, ill get my hands on a phosphate test kit as well as some hygro or other faster growing plant to suck up some excess neutrients (i'll also have them test my nitrates to find out if my test kit is bad). It also looks like they recommend spacing out ferts, so I'm thinking half doses twice a week instead of all at once, makes sence. I'll also start doing twice weekly water changes, and possibly even more in the short term until I get things under control. Once controlled, I can start to look at reducing them back to once per week...we will see.

One thing I did notice is that my cryptocorn and one of my sword plants do have some holes in the leaves. This is consistant with a neutrient difficiency is it not? Would this mean im underfertilized? The substrate is eco-complete and was only added in january, so the iron should still be fine right? Or should I start supplimenting that too?

I later introduced a half hour break at 6pm to break up that last block of light in the evening but it didn't make huge amounts of difference, just made sure I was on top of the algae.

That tank was running at basically 1wpg and I got mad growth, see the thread on it here - you might find some useful info as it was my first real go, so I documented it all pretty well and a lot of people made helpful posts...

Are you shaking the bottles for your nitrate test kit? Are you shaking the vial after adding the drops? Are you waiting 5 minutes to read the results? It seems like the nitrate test is the easiest to screw up if you don't follow the directions exactly. If your nitrate really is zero you should think about adding some KNO3 to bump the nitrate up into the 10-15ppm range, your plants will thank you and your fish won't really care.